Lifting-jack.



PATENT oFFIon.

I Specification of Letters Patent.`

Patented Sept. 26, 1905.

Application led October 18, 1904. Serial No. 228,911l

:To all whom tern/wy concern:

Be it known that I, OARLNELsoma citizen ofthe UnitedStatearesiding at Austin, in

the county of Mower and State of Minnesota, have invented certain new and usefullmprovements in Lifting-Jacks; and I do hereby declare the following to be a full, clear,.and exact description of the invention, such as will enable others skilled in theart to which it appertains to make and use the same.

My invention has for its object to provide an improved lifting-jack, and to such ends it consists of the novel devices and combinations of devices hereinafter described, and defined in the claims. f

The improved jack is illustrated in the accompanying drawings, wherein like charactersindicate like parts throughout the several views.

Referring to the drawings, Figure 1 is a view in side elevation showing the improved jack, some parts thereof being broken away. Fig. 2 is a horizontal section on the line m2 0.02 of Fig. 1. Fig. 3 is a detail, partly in front elevation and partly in vertical section, on the line w3 m3 of Fig. 1, some parts being brokenV away; and Fig. 4 is a View corresponding to Fig. 1, illustrating different positions of the parts, some of the parts being shown in section and some being broken away.

rlhe numeral 1 indicates a hollow pedestal, which, as shown, is rectangular in cross-section and is supported by an expanded base 2, mounted on caster-wheels 3.

Working telescopically within the hollow pedestal 1 is a hollow pedestal-section 4, which, as shown, is rectangular in cross-section, and working telescopically within said extensible pedestal-section 4 is another pedestal-,section 5, which, as shown, is also rectangular in cross-section.

The numeral 6 indicates a pedestal-head, which, as shown, is detachably secured on a trunnion 7 carried vby the upper end of the pedestal-section 5.

On its front and rear face the pedestalsection 4 is formed or provided With ratchetracks 8, and in the same vertical plane therewith the pedestal-section 5 is provided on its front and rear faces with longitudinally-extended ratchet-racks 9. At its sides and near it lower end the pedestal-Section5 is provided with a pair of spring -latches 10, that are formed with shoulders 11 and with outturned ends 12. These spring-latches'lO are adapted `v to be pressed into seats 13, formed in the pedestal-section 5, to permit said pedestal-section 5 to be moved telescopically into the pedestalsection 4. When the pedestal-section 5 is drawn out o f the pedestal-section 4 as far as shown in Figs. 1 and 3, all shoulders 11 of the latches 10 engage the upper end portions of the pedestal-section 4, and the outturned ends 12 of said latches enter into notches formed iny said pedestal-section 4, lthereby locking the two pedestal-sections for common movements in both directions.

The numeral 14 indicates .an operating-,lever, which at'its pivoted end is formed with a rectangular head 15, that embraces the movable pedestal-sections and is pivoted at 16 to bearing-brackets 17, rigidly secured on the sides of the upper end of fixed pedestal-section 1. A pair of spring-pressed pawls 18 are pivotallyv connected, as shown, by rods 19' to the lever-head 15 on opposite sides of pivot 16 and stand in-proper positions for` engagement with the opposite racks of the two 'movable pedestal-sections.

When the pedestal-head 6 is lowered, the pedestal-section 4 will be telescoped into the pedestal-section 1 and the pedestal-section 5 will be telescoped into said pedestal-section 4. Under such adjustments of the pedestal-Secp tions the two pawls 18 will engage with the opposite racks 9 of the pedestal-section 5,

and, asis evident, under vertical oscillations of the lever 14 the said two pawls will be thrown into action `in succession on the said two racks and will raise step by step the pedestal -section 5 until the latches 10 are permitted to spring out and lock together with pedestal-sections 4 and 5, as indicated in Figs. 1 and 3. After the pedestal-section 5 has thus been raised the pawls 18, under continued oscillations of the lever 14, will engage the racks 8 of the pedestal-section 4, and operating in succession thereon will raise the two pedestalsections 4 and 5, as indicated in Fig. 1. To lower the pedestalsections, it is of course necessary to disengage the spring-pressed pawls 18 from theI racks, and this may be done by simultaneously releasing the two pawls or by releasing them in succession' while Vibrating the le-ver 14.

The lifting-jack above described while simple and of small cost is capable of very great extension and is capable of being telescoped into small space.

It will of course be understood that the de- IOl IIO

vice described is capable of modiiication within the scope of my invention as herein set forth and claimed.

What I claim, and desire to secure by Letters Patent of the United States, is as follows:

1. A lifting-jack made up et' a relatively fixed pedestal-section, a plurality of telescopically movable pedestal sections having` ratchet-racks, being in the same vertical plane and a lever pivotally supported by the relatively iixed pedestal-section, and having a pair of pawls working in the plane of said ratchet-racks and operative on the ratchetracks of both of said extensible pedestal-sections, substantially as described.

2. In a lifting-jack, the combination with a relatively iixed pedestal-section, of a plurality of telescopically-extensible pedestal-sections,

one thereof` having a latch for locking it to the coperating' pedestal-section, and both of said extensible pedestal -sections having ratchet-racks, and a lever pivotally supported by said fixed pedestalsection, and provided with a pair of pawls operative en the ratchetracks of said extensible pedestalsections, substantially as described.

3. Ina lifting-jack, the combination with the pedestal-section i supported by a base 2 and provided with bearing-lnackets .17, of an extensible pedestal-sectien L telescopinn' into said pedestal-section 1, and provided with the ratchet-racks 8, the extensible pmlestnl-section 5 telescoping into said pedestal-section 4;, provided with the ratchet-racks S), and the spring'- latches 10, the lever 14C havingl the head 15 pivoted to said bracket 1T and embracing' said pedestal-section 4, and the pawls 1S pivoted to said head 15 and engageable with the said ratchet-racks 8 and 9, substantially as described.

In testimony whereof I aliix my signature in presence of two witnesses.

CARL NELSON.

Witnesses:

J. S. Wool), FRED B. W oon. 

